Best video(s) for FREECAD learning - https://www.youtube.com/playlist?list=PL6fZ68Cq3L8k0JhxnIVjZQN26cn9idJrj
Use these to dial it in - http://www.thingiverse.com/ntrnflxlbs/collections/calibration
http://www.thingiverse.com/ntrnflxlbs/collections/fgtech-i3-2020-upgrades
Spool holder and more there ^^^^


Build Manual REV A- Notes :
Page 5. - Step 2 - Pack all Linear bearings with lithium grease - keep all smooth rods and threaded rods greased up at all times. grease weekly throughout printer's life.
Page 9. Step 5 - At this point align your Sk8's left and right so that the bed moves smoothly .
it might be gritty but should not bind.
Page 11: note hotbed text will be reversed unless you run the wires teh other direction . you must make a stress/strain relief on this wiring.
Page 11 - Step 8 - You'll want to find some thick cut cork sheeting and cut strips to block the air from escaping and stealing heat. you want a sealed area here so that the bed heats up faster and you can remove the cork strips and put a fan for rapid cooling to remove prints. I tried putting a full sheet in as many do but my cork sheet was too thick and effect bed leveling. some even use cardboard.
Page 13 - Step 9 - Number 4 : DO NOT INCLUDE the 3rd Screw and T Nut on the VERTICAL 2020. this will make your Z axis out of alignment and pulls the vertical smoothrods out to the left and right. the motor mount SHOULD NOT be flush with the right side but should be more in towards the printer so the verticle smooth rod is perfectly aligned to the V slot in the vertical 2020 upright extrusion. this ensures it is square up and down to the bottom aluminum mount. the instructions are WRONG here.
Page 13 - Step 2- At this point use my supplied printed anti backlash carrier with a spring captured between two M5 nuts. i've got spare springs and nuts if you need the,.
Page 17  Step 7 - Use my supplied tensioner with a longer bolt and washer - embed the nut in the arm. When you place the bearings in the adjustable tensioner arm,  Pack  bearings with grease and use washers on either side. study movement and ensure free and non-binding.
page 16- step 10 - pack with grease
page 17 - step 15. on the left side of the belt ensure there is only one zip tie and NO spare belt. very short on the left side so that you can get max  LEFT (NEG) X Travel considering the smaller amount of space now that you've installed the tensioner. this works out properly with tweaking , proper X endstop location and the smallest amount spare belt tucked tightly against the X carriage on the left side.
*GENERAL NOTE* Ensure all Locking grub screws on drive pulleys are TIGHT and locked in when the printer is assembled. they should be aligned in such a way so that there is no travel on the belt in any axis then the proper driving axis. after complete assembly and before electronics are connected you should adjust all belts to basically sound like the lowest bass guitar string without cracking plastics. you should make all adjustments and ensure smooth travel before connecting motors to RAMPS as these motors are generators and will cook electronics.
Page 19 - Step 2 - Take time now to tighten heater and thermistor grub screws- Tighten nozzle and hotend. wrap kapton tape nicely around hot end to aid in retention of heater core and thermister. take your fan off and clean anything around the stepper driver hobbed gear.you would probably do best to file and fit your servo and install auto leveler arms at this time. be prepared to file to fit and make adjustment. I can source picture for you to help with this. be prepared with a dremel tool to carefully round out your attached endstop PCB and Arm assembly together so that upon retract it clears correctly. there are firmware configuration steps surrounding this install but we're planning on you using my firmware config which should be pretty damn close to your final assembly.
page 19 Step 12- now is when you add your backlash nut assembly i mentioned earlier. add at the proper time other wise following steps.
page 20 - step 13 - 1 - Pack bearings
page 21 - step 14 - 3 - make sure this pulley lines up when it's all assembled and then lock it down
Page 23 - step 16 - 3 - remember no 3rd T nut and bold here on the VERTICAL 2020 (only two Tnut and Bolt on the HORIZONTAL)
Page 26 - 19 -1 - Mine came with jumpers already on it under the drivers.
26-19-3 - you should use THERMAL ADHESIVE if you have it. the double tape does nothing for you.
If you have a spare heatsink keep it around for use later when you locate the HEATED BED MOSFET. put that heatsink on that mosfet. it helps.
Page 28 - 20 - 5 - Reverse extruder stepper like you did the Z carriage stepper in step 4 above. RED LEFT
Page 32 - Step 3- if you've built an auto leveler then your Z endstop is now on your servo arm. skip this
Page 33 - step 6 -  place this endstop on the LEFT not on the RIGHT as pictured. the text then means (NOZZLE IS JUST TO THE LEFT EDGE OF THE HEATED PRINT BED)
page 34 - step 10 - if you use an auto leveler and plug all of these in as pictured AND move the X endstop to the left then this is the proper location for the endstop switches. the pins are 2 vert in pairs for each axis. each in the pair is either MAX or MIN endstops. meaning you put the endstop on either zero or 200mm of that axis. you define travel direction to home in the firmware.
page 40 - Step 30 -1 - be sure to make everything clean AFTER you've got it printing good and dialed in. I've rewired everything a few times as I've moved things and added things but with the changes and upgrade and direction I've provided this should be pretty much one and done. you need to zip tie any wires to the axis that's moving to provide strain relief . the Kapton tape on the bottom of the Y bed plate is my strain relief. many print cable chain snake style wire conduits. they're common on thingiverse .


FIRMWARE SOFT - Config Guide
Note: I've lost many a print to USB/Power/Noise/CAM Dripfeed failure.
you can fix most of this by: UPS POWER - FERRITE Beads on your USB cord - POWERED USB HUB
or.. Forget all of that and just print from SD CARD !! way better!
I'm probably about to switch to a linux based OS for driving the printer because the HAL is more stable.
Become familiar with https://github.com/MarlinFirmware/Marlin
and http://www.marlinfirmware.org/
Mattercontrol is probably the nicest opensource freeware CAM/Slic3r .. i'd say BETTER than RepItier host! download mattercontrol and give it a run. the settings i've attached are for matter control but you can copy them over to anything- Also, i Can and will need to talk to you about settings and general rules. i can provide configs for rep host, mattercontrol and s3d.
Slic3r is good open source to take cadmodel STL's and cut them to Gcode -
you'll want netfabb basic for model repair.
meshlab for model work.
meshmixer for combinations and it's really great for other general work, alignment, strength and support analysis
Repitier host is a good CAM that calls slic3r

Step 1.  pretty much ignore the book and follow me.
Step 2: Download and install the Arduino software on your computer.
Step 3. Upload my attached firmware in arduino (there is .ino file) to the 2560 board. reviewing configuration.h to become familiar with the settings. you'll be in here a lot .

Step 4: Download and install Mattercontrol
http://www.mattercontrol.com/
Import my INI -
spray your glass evenly with aqua-net in 3 different coats, letting dry. you can use the heated bed to speed this up. you'll know its right when it's got a frosted look. spray more on as needed after prints.
turn the heaters manually, E220/B115 - no need to load up filament yet.
When the extruder hits temp, get your pliers and without fucking the thermistor and heater tighten the hotend to the heat break/cold end and tighten the nozzle to the hot end.
now we should home X and Home Y only. you've got buttons.
Adjust your Endstops on teh smooth rods so the nozzle is in the perfect spot on the bed for the min 0 spot for that axis. (max edge of glass. as far as you'd want to print)
once X and Y is good as far as endstops are and they're locked down. you want to open up your firmware and play with the servo retract/deploy degrees. Send M401 and M402 to adjust until your switch button is perfect when servo is down. upload and save. (configuration.h) reconnect and move on.
now you need to do nozzle offset from servo arm. i'll refer you to this procedure.
Part 5: Configuring the bed leveling probe
This is copy-pasted from the Marlin readme:
Next you need to define the Z endstop (probe) offset from hotend. My preferred method:
    a) Make a small mark in the bed with a marker/felt-tip pen.
    b) Place the hotend tip as exactly as possible on the mark, touching the bed. Raise the hotend 0.1mm (a regular paper thickness) and zero all axis (G92 X0 Y0 Z0);
    d) Raise the hotend 10mm (or more) for probe clearance, lower the Z probe (Z-Endstop) with M401 and place it just on that mark by moving X, Y and Z;
    e) Lower the Z in 0.1mm steps, with the probe always touching the mark (it may be necessary to adjust X and Y as well) until you hear the "click" meaning the mechanical endstop was triggered. You can confirm with M119;
    f) Now you have the probe in the same place as your hotend tip was before. Perform a M114 and write down the values, for example: X:24.3 Y:-31.4 Z:5.1;
    g) You can raise the z-probe with M402 command;
    h) Fill the defines bellow multiplying the values by "-1" (just change the signal)
    #define X_PROBE_OFFSET_FROM_EXTRUDER -24.3
    #define Y_PROBE_OFFSET_FROM_EXTRUDER 31.4
    #define Z_PROBE_OFFSET_FROM_EXTRUDER -5.1

The values I gave you should be pretty damn close.
now - > heat everything up again and you can send a
G28 X0 Y0
G29
this will home X and Y and level the bed.
After leveling finishes, using the controls move to the middle of the bed and then G0 Z0 you should now have .1 (paper width or feeler gauge) of space between the glass and the nozzle. it should just barely catch and feel friction. you can hear the steppers talk barely as you make contact you know you've done it right.
if you are off of the bed and too high or on the bed, make fine adjustments with the software control until you are spot on. take this new location value and this is your Offset Z nozzle/bed offset that you can enter into your slicer or set with G code. My slicer/cam/firmware ignores my G code due to bugs but YMMV . if you look at my starting G code included in the matter control.ini it will show you the codes and offsets. mine is currently set to -.043 and i get a nice first layer.
you'll want to now tune your stepper drivers current and then calibrate your Extruder steps.
to start with the steppers.
you want to send X or Y or z commands to get all steppers to lock up. with your free hand apply a force on the stepper pulley and turn the stepper driver POT counter clockwise until the stepper spins. ensuring the steppers are still locked by software turn up the pot clockwise until they lock up again. add an additional 1/16 turn . then send a long travel command for that axis you are working on and ensure it's not skipping. the idea is you can run this printer for 22 hours and the heatsinks are cool but you never miss steps due to proper tuning of current . do this for all axis. watch your extruder. just set it 220 - load filament and turn it down until it stops. send another 100 mm extrude command and turn it up until it starts . add 1/16 turn and make sure it's smooth.
maintain and monitor along with pulley tightness. trueness of Z threaded rods, lube state, and threaded rod nuts.
at this point you should have XY and Z auto level dialed in. load up filament and set to 220-230 on the extruder and 100-115 for ABS bed adhesion. pick a calibration print and hit go.
.3mm layers are fat and a good start (fast) .2mm is "normal" and what most decent things should be printed in. .1mm is "fine and for high detail high poly or high tensile load parts.
there are many other factors.
Follow this Calibration guide as a reference to understand the details.
http://reprap.org/wiki/Triffid_Hunter's_Calibration_Guide
https://www.youtube.com/watch?v=JZGdMc2ebPo   - Esteps~!

I hope this is enough to get going. i'm sure i missed a lot .


ABS - 220 Ex- 115 BED
Nozzle clogs :